Wexmar provides custom hub and yoke machining for drivelines, couplings, power transmission equipment and rotating assemblies. Our Canastota, New York shop produces CNC machined hubs, flange hubs, coupling halves, end yokes and clevis-style yokes on Mazak and Doosan lathes and 4-axis horizontal machining centers. The common thread in all of these parts is a bore that must line up with everything else, and our setups are built around that bore.
What hubs and yokes do and who buys them
A hub connects a shaft to a gear, pulley, wheel or flange. A yoke connects a shaft to a universal joint or pivot, with cross holes that must be coaxial and square to the bore. Typical buyers include:
- Power transmission, coupling and driveline OEMs
- Industrial equipment and material handling builders
- Agricultural, mobile and off-highway equipment makers
- Defense and government programs with build-to-print driveline parts
How our custom hub and yoke machining works
Turning hubs and flanges
Hubs, flange hubs and coupling halves are turned on our lathes, with the bore, pilot and flange face finished in one chucking. Live tooling and Y-axis cut bolt circles, set screw holes and keyways without a second setup, and the Mazak Multiplex 6300Y finishes both ends in one cycle. See CNC turning.
Horizontal milling yokes
Yokes are turned for the bore and hub, then moved to our Mazak horizontal machining centers. Located on the finished bore, the ears are milled and the cross holes bored from both sides using the 4th axis, so both cross holes share one axis that is square to and intersects the bore axis. Pallet changers help on production lots. See CNC milling.
Splines and keyways
Keyways are machined to standard in-house. Internal splines that require shaping or spline broaching are completed through qualified outside processors.
Typical materials
- 1045, 4140 and 4340 steel for hubs, yokes and couplings, often heat treated
- Steel forgings supplied by the customer or sourced through qualified outside processors
- 6061 and 7075 aluminum for lightweight hubs
- 303, 316 and 17-4 PH stainless for washdown and corrosive environments
- Titanium for strength-to-weight applications
Critical features and how we hold them
- Bore fit: bored to a slip, transition or interference fit, or to a taper for bushing systems.
- Flange face runout: faced with the bore for square mounting.
- Cross hole coaxiality: yoke cross holes are bored from one setup using the 4th axis.
- Cross hole to bore perpendicularity and intersection: set by locating on the finished bore.
- Bolt circle position: positioned from the pilot and bore axis.
- Keyway: width and depth to standard, centered on the bore.
Typical tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Hub bore | +/-0.0005 in | +/-0.0003 in |
| Flange face runout to bore | 0.001 in TIR | 0.0005 in TIR |
| Yoke cross hole diameter | +/-0.0005 in | +/-0.0003 in |
| Cross hole coaxiality | 0.001 in | 0.0005 in |
| Cross hole perpendicularity to bore | 0.001 in | 0.0005 in |
| Bolt circle true position | 0.005 in | 0.002 in |
| Bore finish | 63 Ra | 32 Ra |
Values are typical and depend on size and material. The quote confirms each callout.
Design notes
Dimension yoke cross holes from the bore axis rather than from outside surfaces, which matches how the part is machined and inspected. If the part is heat treated, state whether bores and cross holes are finished before or after hardening. On forged yokes, a clear datum scheme and adequate machining stock prevent problems at first article.
Secondary operations
Heat treat, black oxide, zinc and phosphate coatings, anodizing and painting are completed through qualified outside processors. Welding of weld yokes to tubes is not done in-house and is also arranged through qualified outside processors when requested.
Quantity patterns
Orders range from prototype sets and replacements to production runs of hundreds per release. Fixtures for yokes are retained for repeat orders, so later releases are located and inspected the same way as the first article. Related parts include pulleys.
Inspection
Bore size, runout, cross hole coaxiality and perpendicularity are verified on our Brown and Sharpe CMMs. FAI in AS9102 format, CMM reports, material certs and heat-lot traceability are available.
Getting a quote
Send the drawing, material, heat treat requirements and quantity. You can upload a drawing for an instant estimate, and an estimator will confirm price and lead time. Call (315) 400-2654 to discuss hubs and yokes.